Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The alteration of the structural organization of dermal connective tissue was studied by light and electron microscopy and by biochemical techniques in normal human and in diabetic patients using skin biopsies. Part of the tissue was used for light and electron microscopy, the rest was incubated in the presence of 3H-lysine for four hours. The 3H-lysine labelled biopsies were submitted to a sequential extraction procedure in order to obtain representative macromolecular fractions containing the matrix macromolecules. The extracts were analyzed for their chemical composition and radioactivity. Electron microscopy revealed ultrastructural modifications of the fibroblasts, of the collagen and elastic fibers in the diabetic dermis. Fibroblasts contained an increased amount of electron dense deposits in the cytoplasm and dilated endoplasmic reticulum. The collagen bundles were dissociated. Elastic fibers under the epithelial basal laminae were fragmented or absent. The incorporation pattern of 3H-lysine into these macromolecular fractions was different in the normal and diabetic skin biopsies. The percentage of total radioactivity incorporated increased significantly in the 1M CaCl2 extractable fraction an in the 6M urea extractable fraction and decreased significantly in the collagenase and elastase extracts in diabetic skin biopsy. These results demonstrate the existence of morphological and biochemical alterations in diabetic connective tissue (dermis) reflecting alterations in the relative rates of synthesis and/or degradation of the intercellular matrix macromolecules as well as of their microarchitectural arrangement.
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PMID:[Structural and biochemical alterations of human diabetic dermis studied by H-lysine incorporation and microscopy]. 18 19

Explants from rabbit aortic media were incubated in MEM medium supplemented with 14C-lysine and with 10 p. 100 hyperlipemic (type IV and V) or normal human serum respectively. The incubated fragments were extracted at increasing ionic strength. The insoluble collagen and elastin were hydrolysed with collagenase and alcoholic potassium hydroxyde respectively. The radioactivity was determined in the extracts and the radioactive labelling profile of proteins was investigated on polyacrylamide gel electrophoresis in SDS. With the exception of the collagenase extract (polymeric collagen) the incorporation of the radioactivity into insoluble collagen is not altered or increases. These the incubation was carried out in the presence of hyperlipemic serum. Incorporation of the radioactivity into insoluble collagen seems not to be altered. These results show a decreased protein synthesis with a relative increase in the biosynthesis of polymeric insoluble collagen in the aortic media incubated in the presence of hyperlipemic serum.
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PMID:Action of human hyperlipemic sera on the biosynthesis of intercellular matrix macromolecules in aorta organ cultures. 18 73

More than 90 percent of the cells isolated from the mammary gland of lactating rats with 0.1 percent collagenase were viable by dye exclusion. Myoepithelial cells comprised about one-third of the mammary cells and appeared to be morphologically intact in electron micrographs. [(3)H]Oxytocin-binding activity was localized in an enriched myoepitheial cell fraction obtained by density gradient centrifugation of the isolated cells. The amount of [(3)H] oxytocin bound at 20 degree C and pH 7.6 was proportional to the concentration of oxytocin and the number of cells, reaching a steady state by 40 min. About 0.45 fmol of oxytocin were bound per 10(6) cells. There was a single class of independent binding sites with an apparent K(d), estimated from equilibrium conditions, of 5 nM. This value agrees within experimental error with the value calculated from the ratio of reverse to forward rate constants (5.8 x 10(-4)s(-1) and 2.2 x 10(5) M(-1)s(-1), respectively), consistent with a single-step model for the interaction of oxytocin with binding sites on the cells. Erythrocytes bound only 3.5 percent of the amount of oxytocin bound by an equal number of mammary cells. Oxytocin analogues competed with [(3)H]oxytocin for binding sites in the following order: [deamino]oxytocin > [4-threonine]oxytocin > oxytocin > [O- methyltyrosine]oxytocin > [8-lysine]vasopressin; [lysine]-bradykinin and [4-proline]oxytocin were not inhibitory in the dose ranges tested. These results demonstrate that isolated mammary cells possess oxytocin receptors with properties comparable to those found in broken mammary cell preparations.
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PMID:Binding of [3H]oxytocin to cells isolated from the mammary gland of the lactating rat. 19 65

1. A method is described for the preparation of isolated cells from guinea pig liver. This involved perfusion in situ, in the non-physiological direction, with collagenase. 2. The cell yield was 20--30%, comparable with those from the livers of other species. 3. The ratio of lactate dehydrogenase to glutamate dehydrogenase in the cells was similar to that in vivo, indicating that there was negligible leakage of cytoplasmic enzymes. 4. The concentrations of K+ and adenine nucleotides were initially lower than in the perfused liver; normal values were obtained on incubation, particularly in the presence of substrate. 5. The L-lactate: pyruvate ratio is 16:1, close to established values. The total beta-hydroxybutyrate: acetoacetate ratio indicates that the mitochondrial redox state is more oxidised than in the perfused liver, but the intracellular ratio is similar to that of the intact liver. 6. Rates of gluconeogenesis and ureogenesis, are within the physiological range. Maximal gluconeogeneis from L-lactate was preceded by a lag period. L-lysine stimulated glucose production from L-lactate but did not abolish the lag phase. 7. The effects of aminooxyacetate and octanoate on L-lactate gluconeogenesis were similar to those in the perfused liver.
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PMID:Preparation and characterization of isolated parenchymal cells from guinea pig liver. 19 81

A fibrillar collagen molecule was extracted from the upper thoracic aorta of an old burro (Equus asinus). Presence of the collagen in the extract was determined by amino acid analysis, scanning and transmission electron microscopy, incubation with collagenase, and assays of its platelet-aggregating capacity by "aggregometry". Based on the amino acid rations of proline/hydroxyproline and lysine/hydroxylysine, the collagenous protein most nearly resembles type I of 4 main published types of collagen. Quantitative assays of the collagen as a mediator of platelet aggregation showed human platelets more sensitive and sheep platelets slightly less sensitive than burro platelets. Incubation with collagenase abolished platelet aggregation capacity and converted the fibrillar collagen to a gel-like mass. Incubation with galactose oxidase neither lessened nor intensified the collagen-mediated platelet aggregation. Incubation with burro plasma decreased platelet aggregating activity and changed the collagen ultrastructure (demonstrated with scanning electron microscopic imaging). The significance of a naturally occurring plasma (protein) factor(s) which may have a regulatory role in reducing the chemical activity of the fibrillar collagen molecule with platelets is also discussed.
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PMID:Burro aortic collagen: platelet aggregating activity and ultrastructural changes induced by plasma. 20 46

Renal gluconeogenesis was studied in suspended tubule fragments isolated by collagenase treatment of rat kidney cortices. Angiotensin II increased glucose formation from pyruvate, lactate, and to a lesser extent from oxoglutarate and glutamine, but not from other substrates such as malate, succinate, dihydroxyacetone or fructose. Stimulation was significant with peptide concentration exceeding 1 . 10(-8) M and was also shown with an 8-Sar derivative. Other peptides such as 4-Ala-8-Ile-angiotensin II, hexapeptide and bradykinin had no effect. The stimulatory action of angiotensin II was additive to that of L-lysine, and 3',5'-adenosine cyclic monophosphate, suggesting a different mechanism of action. In the presence of maximally stimulatory concentrations of oleate, phenylephrine and 3',5'-guanosine cyclic monophosphate, however, the stimulatory effect of angiotensin II was absent. Cyclic GMP levels, however, did not increase in tubules after angiotensin II and phenylephrine addition, making a messenger function of this nucleotide unlikely. Omission of Ca2+ from the medium markedly reduced basal gluconeogenesis but did not result in a complete loss of angiotensin II effect. Reduction of medium potassium to 2 mM, however, increased basal gluconeogenesis and blunted the peptide effect. 1 mM ouabain was also able to inhibit the stimulatory effect of angiotensin II. Therefore changes in intracellular potassium levels are discussed as a possible mechanism of angiontensin action, whereas calcium seems not to be specifically linked to this metabolic action of angiotensin on the proximal tubule.
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PMID:Stimulation of renal gluconeogenesis by angiotensin II. 45 78

The non-collagenous N-terminal segment of type I procollagen from dermatosparactic sheep skin was isolated in the form of the peptide Col 1 from a collagenase digest of the protein. The peptide has a blocked N-terminus, which was identified as pyrrolid-2-one-5-carboxylic acid. Appropriate overlapping fragments were prepared from reduced and alkylated peptide Col 1 by cleavage with trypsin at lysine, arginine and S-aminoethyl-cysteine residues and by cleavage with staphylococcal proteinase at glutamate residues. Amino acid sequence analysis of these fragments by Edman degradation and mass spectrometry established the whole sequence of peptide Col 1 except for a peptide junction (7--8) and a single Asx residue (44), and demonstrated that peptide Col 1 consists of 98 amino acid residues. The N-terminal portion of peptide Col 1 (86 residues) shows an irregular distribution of glycine, whereas the C-terminal portion (12 residues) possesses the triplet structure Gly-Xy and is apparently derived from the precursor-specific collagenous domain of procollagen. The central region of the peptide contains ten cysteine residues located between positions 18 and 73 and shows alternating polar and hydrophobic sequence elements. The regions adjacent to the cysteine-rich portion have a hydrophilic nature and are abundant in glutamic acid. The data are consistent with previous physicochemical and immunological evidence that distinct regions at the N- and C-termini of the non-collagenous domain possess a less rigid conformation than does the central portion of the molecule.
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PMID:Amino acid sequence of the N-terminal non-collagenous segment of dermatosparactic sheep procollagen type I. 47 72

Type I procollagen secreted by matrix-free chick embryo tendon cells was labeled with L-[3,3'-3H] cystine and purified by DEAE-cellulose chromatography. After bacterial collagenase digestion, the NH2- and COOH-terminal propeptides were partially characterized by ion exchange chromatography and gel filtration. Similar experiments were then conducted after labeling with either D-[6-3H] glucosamine, D-[2-3H] mannose, or D-[U-14C] glucose. On the basis of these studies and subsequent carbohydrate analysis, it was concluded that the COOH-terminal peptide contained greater than 90% of the radioactive carbohydrate which consisted predominantly of glucosamine and mannose with traces of galactosamine and galactose. Only radioactive glucosamine could be detected in the NH2-terminal propeptide. Under conditions which inhibit hydroxylation of lysine and glycosylation of hydroxylysine, unhydroxylated procollagen (protocollagen) could still be labeled with [3H] glucosamine and [3H] mannose. This suggested that glycosylation of the propeptides is at least initiated at the level of the rough endoplasmic reticulum.
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PMID:Localization and partial composition of the oligosaccharide units on the propeptide extensions of type I procollagen. 61 65

Homologous saphenous veins where implanted in the arterial circilation (femoral artery) of dogs for various times (1 to 9 months, most data given for 3 months). After this period, the in vitro biosynthesis of intercullar matrix macromolecules was studied by incubating the veins in organ culture conditions in the presence of 14C-lysine for 3 days. A fractional extraction procedure was used to obtain representative macromolecular extracts for the determination of chemical composition (hydroxyproline, hexosamines) and radioactivity. Neosynthesis of elastin was considered as valid criteria for the adaptation of the veinous wall to the new (arterial circulatory) conditions. The chemical composition of the grafted veins was different from that of the nongrafted, controlateral saphenous veins suggesting a molecular remodeling of the grafted veinous wall. Radioactive lysine was incorporated in all macromolecular fractions of grafted and control veins. The specific radioactivity of the extracts obtained from grafted veins was higher than that obtained from the control veins. The only exception was the collagenase extract (containing mainly the polymeric collagen) which had a somewhat lower radioactivity in the grafted vein. The incorporation of lysine in the elastin fraction increased by a factor 10 in the grafted vein as compared to the non-grafted veins. Radioactive desmosine could be demonstrated in the elastin fraction. It appears therefore that the veinous wall could adapt its biosynthetic capacity to the new circulatory conditions by increasing considerably the biosynthesis of elastin. This is accompanied by an increase of the synthesis of other macromolecules and a significant remodeling of the macromolecular structure of the vessel wall.
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PMID:Biosynthesis of elastin and other matrix-macromolecules in veinous arterial prosthesis. 79 9

External jugular veins that had been subjected to the hemodynamic stresses produced by experimental arteriovenous anastomosis developed 2% increased total protein contents and 17% increased collagen contents. When the stressed veins were homogenized and extracted with saline solutions, statistically significant increases in the saline-soluble proteins and in the saline-soluble collagen (87% and 267%, respectively) were observed. Increased amounts of low molecular weight peptides were found in the extracts. A fraction of these peptides could be degraded by Clostridium collagenase. The saline extract also contained proteins which resembled by their amino-acid composition the acidic structural proteins of the connective tissues. Additonally, in 3 dogs so tested, changes were found in the hydroxylation and glycosylation of lysine from gelatin extracts as well as in the lysine and desmosine contents of the insoluble elastin fractions. This is the first demonstration of a hemodynamically induced increase in the saline solubility of connective tissue proteins in the absence of dietary manipulations.
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PMID:Hemodynamically-induced increase in soluble collagen in the anastomosed veins of experimental arteriovenous fistulae. 126 60


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